ALTERED PARAFOVEAL MICROVASCULATURE IN TREATMENT-NAIVE CHOROIDAL MELANOMA EYES DETECTED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

Purpose: To determine whether parafoveal microvascular changes have occurred in choroidal melanoma eyes before radiotherapy. Methods: A retrospective cohort study included 30 consecutive patients with unilateral choroidal melanoma. The microvascular structure was analyzed by optical coherence tomography angiography. Fellow eyes served as control for affected eyes. Results: Optical coherence tomography angiography demonstrated no difference in superficial foveal avascular zone (P = 0.316), but showed significant enlargement in deep foveal avascular zone (P < 0.0001) in affected eyes as compared with fellow eyes. It also showed significant decrease in superficial (P = 0.004) and deep (P = 0.0003) capillary vascular density (CVD). In subgroup analyses, the presence of subretinal fluid contributed to significant enlargement of deep foveal avascular zone (P < 0.0001) as well as reduction in superficial (P = 0.0001) and deep (P = 0.001) CVD. By linear regression, greater tumor diameter correlated with reduction in deep CVD (y = 20.42x + 1.01, P-slope = 0.021); greater tumor thickness correlated with reduction in both superficial (y = 20.67x + 0.24, P-slope = 0.039) and deep (y = 20.82x + 0.56, P-slope = 0.002) CVD. Conclusion: Optical coherence tomography angiography documented significant enlargement of deep foveal avascular zone as well as reduction in superficial and deep CVD in affected eyes. These findings correlated with the presence of subretinal fluid and increasing tumor size, suggesting that tumor-related factors contribute to parafoveal microvascular ischemia.